The present invention generally relates to a component in a safety restraint system, and more particularly to a compact buckle pretensioner.
Buckle pretensioners, or belt tightening units, are typically used to remove slack about the occupant. These pretensioners typically utilize a housing having a movable piston. The piston is propelled down the housing by a pyrotechnic charge. The piston is coupled directly to the buckle so that for each unit of movement of the piston, the buckle is moved a similar distance.
It is an object of the present invention to provide an improved compact buckle pretensioner. A further object of the present invention is to provide such a pretensioner with a mechanical advantage, that is the ability to move the buckle a distance that is greater than the movement of the corresponding piston. Accordingly the invention comprises: a pretensioner comprising: a housing with a bore; a piston slidably received within the bore, the piston further including a pulley surface at one end thereof; a flexible link having a first end fixedly connected to the housing, a medial portion slidably positioned about the pulley surface and an opposite end adapted to be connected to a buckle; first means for propelling the piston from a first, static position to a second position to affect a mechanical advantage in the movement of the buckle.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.